Yeah, they still end up leaking, It's really not an issue in my location. I just removed the orginal wire taps off of my trailer brakes on the axle from 1998. They were still working, I needed to drop the axle.
I want to mount the coils across the edge of the firewall where the red line is. ECU will be inside the tub on the back side of the firewall extension where the yellow square is. There's 15"-18" between where the ecu and the coils. I'm more concerned with interference from the coils messing with the ecu. I've been told it doesn't matter with GM ECU's.